I just went from iPhone to Android and am happy so far. I did not even look at a WinPhone.
The key thing for Nokia phones is the best cameras on the market and very solid (hard to break) design.
I love my Nokia 920 and can’t wait for the 1020.
Nokia Lumia 520/521 is the best-selling Windows Phone
http://www.anandtech.com/show/7177/nokia-lumia-521
That phone will replace our small "take it anywhere" camera, which still, at this point, takes better pics than any camera.
My wife & I both upgraded to Nokia Lumia 928 WP8 phones right after Verizon started offering them, sometime in late May (last month on this graph). We really like them.